Cannot secure wireless network

I switched my ISP to Comcast yesterday, despite all the complaints I'd heard about their support, because I felt it was my only option for getting enough bandwidth for HD streaming.

Unfortunately, no one asked me if I was going to need wireless access to my network, and I didn't think to mention it. It was only after the installer left that I realized it wouldn't work. The cable modem does support Wi-Fi, so I called Comcast support, and reached a very nice lady who wasn't able to give me much help.

What I've found is that I can not access my network with a password. I've tried over and over, both on a Windows 7 system and a Mac. I set it up on the modem with a WPA2-PSK (AES) password and match that on my other computers, but it continues to tell me that the password is invalid. I do have wireless access if I leave the network completely open, which I had to do to get online to post this.

The Following User Says Thank You to junebug For This Useful Post:

Thanks, junebug. I tried all your suggestions as well as doing hard reset on the modem a couple of times, with no success.

However, I called tech support for the third time and was finally able to get things working with the default network name and password. Now I'm wondering if it's really as secure as she claimed it is....

However, I called tech support for the third time and was finally able to get things working with the default network name and password. Now I'm wondering if it's really as secure as she claimed it is....

In order to really give an answer to the question above.Need to know what brand & model of your router.

Problems cannot be solved by the same level of thinking that created them. -Albert Einsten

chowur, it's an SMC, Model SMCD3GNV--my first experience ever with a cable modem.

Paul, the passphrase I have been using is 24 characters, which I thought was sufficient for my home network that no one is going to want to put a lot of effort into hacking. But believe or not, the modem allows a maximum of 16 characters, and letters and numbers only--no special characters. The default password is 16 characters, and is based on, but not the same as, the serial number.

Wireless passwords need to be certain lengths to work, in your case you should stick to 16 characters as the router is designed to work this way.
You could test it with 16 sequential digits to see if it behaves.

Here's a question & suggestion from (far) right field: Have you installed Comcast's "Constant Guard Protection Suite"? It includes a component called GuardedID that can mess with various passwords. I had to do similar detective work to clean up a family member's laptop when he reported identical wireless login failures. Here's an item on the Comcast forums that addresses the topic: http://forums.comcast.com/t5/Securit.../927921#M80040
Fix in our case was to do a straight uninstall of GuardedID.